Single operation door lock boring device



Sept. 8, 1970 H. A. KOEHLER 3,527,275

SINGLE OPERATION DOOR LOCK BORING DEVICE Filed Jan. 5, 1968 2 Sheets-Sheet 1 FIG.|.

INVENT OR HERMAN A. KIOEHLER ATTORNEYS H. A. KOEHLER SINGLE OPERATION DOOR LOCK BORING DEVICE Sept. 8, 1970 2 Sheets-Sheet 2 Filed Jan. 5, 1968 INVENTOR HERMAN A. KOEHLER FIG. 3

ATTORNEYS United States Patent 3,527,275 SINGLE OPERATION DOOR LOCK BORING DEVICE Herman A. Koehler, 3674 SW. 25th St, Miami, Fla. 33133 Filed Jan. 3, 1968, Ser. No. 695,470 Int. Cl. B23b 49/00; 1327c 3/08 US. Cl. 144-93 4 Claims ABSTRACT OF THE DISCLOSURE A single operation door lock boring device comprising a locating and cutting part, and a drilling part, said locating and cutting part including a circular sharp edge portion defining a cup, and a peripherally threaded shaft normally projecting from the center of the cup, said drilling part comprising a drilling bit having a diameter identical to that of said cup and including two elongated shaft portions that normally project at opposite sides of said bit in longitudinal alignment therewith, said bit and shaft portions being internally threaded and having the same diameter as said peripherally threaded shaft, whereby, by means of an applied power source both parts come in close contact by telescopic approximation while drilling and cutting in a single operation a door lock bore from both sides of a door.

This invention relates, in general, to a wood boring device. More particularly, the invention relates to a composite wood boring device that makes a burrless and splinterless lock bore in a single operation.

The invention is of general utility for boring panels, and is particularly useful in making lock bores in doors and similar structures.

Heretofore, boring splinterless and burrless bores in doors included several time consuming carpentering operations requiring: marking on both sides of the door; aligning both markings in a 90 angle in respect to the plane of the door; partially drilling the bore with a suitable bit until a portion of the bit showed at the other side of the door; drilling in the opposite direction to complete the bore and, finally erasing or sanding the bore to leave a finished and smooth surface. This standard technique is plagued with many problems. For example, perpendicular alignment is difficult to maintain during drilling; additional tools are required for marking and locating the bore orientation since the bit cannot withstand the impact of a hammer; the bit may lock or bind during drilling requiring much effort to free and remove the bit from the bore.

The present invention avoids the above problems and effects a bore in a single reliable operation. Briefly described, the invention comprises a cutting and locating part and a drilling part. The locating and cutting part includes a circular cup portion with a sharp beveled edge having a concave recess defining the cup interior, and a peripherally threaded shaft that normally projects from the center of the cup outwardly thereof. The drilling part comprises a drilling bit, preferably a butterfly bit having a diameter identical to that of the beveled edge, and structurally includes two shaft portions normally projecting at opposite sides of said bit in longitudinal alignment therewith. Said bit and shaft portions are internally threaded for threading onto the shaft of the locating and cutting part.

When a power source is applied to the drilling bit, upon threaded engagement with the peripherally threaded shaft, the inner threading of the bit draws the parts together by telescopic approximation, to a point where both parts make contact completing while drilling in a single operation a door lock bore from opposite sides of the door.

3,527,275 Patented Sept. 8, 1970 "ice It is, therefore, an object of the present invention to provide a new and improved boring device that, for the first time, avoids and solves the above mentioned problems.

A further object of the present invention is to provide a lock boring device attached to a power drill that performs in a single operation a burrless and splinterless bore through a panel, door or the like.

Another object of the present invention is to provide a door lock boring device that drills a bore through a door without drift, shift, or elongation of the bore.

An additional object of the invention is to provide a door lock boring device that, by virtue of its design, can be hit with a hammer for marking or locating the opening to be bored.

A further object of the invention is to provide a door lock boring device that can be readily freed from the bore in the event it becomes seriously bound.

A still further object of the invention is to provide a door lock boring device, having composite parts, that telescopically approximate as a unit while cutting and drilling a bore through a door to develop a smooth and uniform bore in a single operation.

To effect these and related objects which shall become apparent as the description proceeds, the invention resides in the combination, construction, and arrangement of parts as shall be hereinafter more fully described, illus trated in the accompanying drawings, and pointed out in the claims hereunto appended.

With reference to the drawings a preferred embodiment of the invention is illustrated.

FIG. 1 is a side elevation illustrating in section the preferred embodiment of the invention, installed in a door, and ready for the boring operation.

FIG. 2 is a side elevation illustrating in section the preferred embodiment of the invention, installed in a door, and having completed a door lock boring operation.

FIG. 3 is an end elevation of the cutter taken along line 3--3 of FIG. 1.

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1.

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 1.

In the above mentioned figures the cross-sectional representation of the door has been omitted for the sake of clarity in the last two figures.

FIGS. 1 and 2 show that the device comprises a locating and cutting part 2 and a drilling part 4. By telescopic approximation of parts 2 and 4 a door lock opening 32 is formed in a single operation. The truly perpendicular bore thus performed is devoid of burrs or splinters and requires no further drilling or erasing.

The cutting and locating part 2 includes a circular metallic cup 3 having a beveled edge 11 and a reduced section 9 that defines a concave recess generally shown as 9. An abutment 5 is defined at the center of said concave recess 9, however, if desired, the bottom of the cup can function as the abutment as described below. Shaft 13 is peripherally threaded 15 and has one end secured to abutment 5 coaxial with cup 2. Shaft 13 projects outwardly, in normal orientation, from said recess 9 beyond said beveled edge 11. Cutter 2 further includes a protuberance 7 positioned in the center of the external surface of cup 3. Protuberance 7 preferably has a square or hexagonal profile and provides a nut for wrench engagement in the event the parts bind during operation. Protuberance 7 further provides a hammer blow withstanding reinforcement.

It should be noted that the above mentioned structures have their centers in horizontal alignment. It should also be noted that the above mentioned structures have their common horizontal axis 12 defining a 90 angular incidence with both sides of door 30.

The drilling part of the device includes a wood boring bit 4, preferably a butterfly bit, having an elongated enlarged part 31, and elongated shaft portions of reduced diameter 17a and 17b that project outwardly from both sides of bit 4 in coaxial alignment therewith. Bit 4 defines an internally threaded bore 19 having the same diameter as said peripherally threaded shaft 13 so as to threadedly engage therewith. Threaded bit 4 receives and threadedly approximates toward said cutting and locating part 2 as described below.

Drilling bit 4 further includes a pair of sharp drilling flanges 23 positioned at opposite diameter ends and a pair of angularly sloped sharp edges 25 facing in the same cutting direction. It should be noted that said drilling part components share a common central axis.

Cup 3 bounded by said bevel edge 11 is of the same diameter as that defined between edge flanges 23 on bit 4. With this diameter correlation parts 2 and 4 develop in a single operation a uniformly dimensioned and horizontally aligned bore 32 when said parts telescopically approximate towards each other from opposite sides of the door.

The length of elongated portion 17a on drilling bit 4 is such to allow beveled cup edge 11 and the sharp bit edge of flange 23 to engage in close contact when portion 17a contacts abutment 5 in cup 3. This arrangement prevents damage to flanges 23 and edge 11 after the bore is formed.

In operation, shaft 13 is inserted through a pilot opening 29 normally provided in new door panels. Subsequently, cup 3 is located in fixed marking position by a number of hammer blows on protuberance 7. The hammering drives edge 11 through the surface of door 30 severing the wood grain. Bit part 17a is threaded onto shaft 13 from the opposite side of the door until it is drawn against the door. The foregoing completes the assembly preparation of the device to a effect in a single operation a door lock bore.

A power source 27 is then connected to portion 17b of the bit which revolves upon its axis while flanges 23 and cutting edges 25 drill through the adjacent side of the door. Due to the threaded engagement of shaft 13 and portion 17a, beveled edge 11 of cup 3 cuts into the opposite side of the door while at the same time bit 4 bores from its side. This action continues until portion 17a and abutment 5 meet at which time the bore is fully formed. Since the edge of flange 23 meets edge 11 somewhere between the outer faces of door 30, the bore upon completion of the operation as described is already finished and burrless. Upon completion, parts 2 and 4 are removed and the bore is ready for use.

The structures herein described constitute a preferred embodiment of the invention. It should be understood that various modifications might be adopted without departing from the spirit and scope of the invention.

What is claimed is:

1. A single operation door lock boring device comprising a locating and cutting part and a drilling part, said locating and cutting part including a circular cup having a beveled edge, an abutment defined Within said cup, and a threaded shaft normally projecting from the center of the cup outwardy thereof, said drilling part including a drilling bit having threaded portions projecting at opposite sides thereon in longitudinal alignment with said bit and being threaded with said shaft, said bit further including at least a pair of diametrically opposed sharp edge flanges and at least a pair of cutting edges, the outer diameter of said circular cup being equal to the distance between said sharp edge flanges so that when the bore is completed, the flanges abut the circular cup, and power means operatively coupled to said bit to rotate the same so that the bit draws said locating and cutting part, While the drilling part simultaneously perforates a door lock bore through a door by telescopic approximation of said parts.

2. The single operation door lock boring device of claim 1 wherein the component structures of said locating and cutting part, and said drilling part have their centers in coaxial horizontal alignment.

3. The single operation door lock boring device of claim 1 wherein said cup has a protuberance defined on the center of the outer surface of said cup in coaxial alignment with said locating and cutting part and said drilling part, said protuberance affording impact strength to the cup and being suitably shaped to permit engagement with a wrench-like device.

4. The single operation door lock boring device of claim 3 wherein said protuberance has a square profile and a nut shape.

References Cited UNITED STATES PATENTS DONALD R. SCHMN, Primary Examiner US. Cl. X.R. 77-62 

